But the BRIC nations as a whole—a force in the global economic conversation since the acronym was coined by Goldman Sachs to refer to the high-growth economies of Brazil, Russia, India and China—are becoming an increasing naval presence on the high seas. One reason is simple nature—when nations become wealthier, they tend to build up their fighting capabilities. But another is natural resources—all four nations either want to buy or sell oil and natural gas, and they are venturing further and further to do so.

A paradox is that while the shift challenges US primacy on the high seas, the US itself—because of its oil and gas boom—is driving part of the BRIC naval expansion.

Because it is providing for more and more of its own energy requirements, the US is importing much less African and Middle East crude, and the chief new buyers replacing it are BRIC nations—the US is about to be displaced by India as the largest buyer of Nigerian crude oil, for example. “It is only a matter of time before we see Indian ships in the South Atlantic [to patrol the coast of West Africa],” Brahma Chellaney, of the Center for Policy Research in New Delhi, told the Financial Times.

Such a shift—an expansion of Indian forces from the Indian Ocean to the Atlantic—would be huge. But so is the entirety of the BRIC naval activity. Russia has been a maritime power since Peter the Great, and Zheng He made China a major 15th century naval power. But Russia all-but stopped venturing outside former Soviet waters in 1992, and China has not fielded a major navy in the six centuries since Zheng He. Brazil and India have largely stuck to their own shores.

Beijing’s and Moscow’s naval assertiveness, particularly in Syria and the South and East China seas, attracts most of the attention. But India is building a second aircraft carrier, and may have three by 2020, along with four nuclear-powered submarines and various other modern ships. In 2012, India dispatched warships to the Horn of Africa, the Red Sea and the western Mediterranean. And in 2008 and 2010, India and Brazil conducted joint naval operations with South Africa on the Indian Ocean side of Africa.

In November 2012, some 10,000 Brazilian sailors and soldiers conducted an exercise called “Operation Atlantico 3,” meant to demonstrate the country’s ability to defend its offshore oilfields.

A greater BRIC role on global trade routes is not a negative development for the US, says Ely Ratner of the Center for a New American Security in Washington, DC.

“There’s no reason the American taxpayer should be subsidizing the freedom of navigation in the Indian Ocean when emerging powers like China and India are both increasingly capable of providing this service and are the primary beneficiaries of open sea lanes between Africa, the Middle East and Asia,” Ratner told me in an email exchange. “These trends will only become more prominent as the United States becomes even less reliant on direct access to Middle Eastern oil.”